Mixed forests of broadleaves and conifers, thanks to their high productivity and high biodiversity, are the most valuable part of the growing stock in Serbia. The aim of this research was to analyze the mixed old-growth forests of fir, spruce and beech in the reserve “Ra anska ljivovica“ so as to define the laws which could be applied in the future forest management on Mt. Tara. The research was based on the data of six periodic complete inventories followed by standard dendrometric and statistical processing. Forest structure was similar to the typical selection structure. The recruitment dynamics (except beech) was relatively favourable, with the ratio to dead trees amounting to 1.72. The number of trees and the volume increased constantly, attaining 422.2 trees ha-1, i.e. 800.3 m3 ha-1, and the volume increment was above 12 m3 ha-1, despite a slight drop. Silver fir was the protagonist of the selection structure and productivity. It is necessary to stimulate the survival and development of beech at the concrete site, to examine the balanced number of trees and volume, and to investigate the relationship between the number of recruited trees and the stand volume.